AMERICA'S LONGEST TUNNEL.

Auckland Star, Volume 55, Issue 152, 28 June 1924, Page 24

AMERICA'S LONGEST TUNNEL.

SIX-MILK BORE IN COLORADO. Work was commenced last year on what, on completion, will be the longest railway tunnel in the Uulted States. This undertaking is situated in Colorado, and is being constructed under unusual circumstances, the State of Colorado having itself financed the work by the issue of bonds, and appointed a commission to carry the enterprise through. The tunnel will connect two points on the Denver and Salt Lake Railroad, and will pierce the Continental Divide over which this line at present passes at an elevation of 11,660 feet above sea level. A length of tunnel of (5.09 miles will be substituted for a distance by the present alignment over the pass, of 23 miles, to say nothing of a saving in elevation of 2400 ft. Some account of the scheme is given in a recent issue of the "Railway Review," in which it is stated that no less than 41 per cent of the operating expenses of this railway, commonly known as the MolTat road, go in fighting snow blockades in the winter months, the bulk of this being connected with work in the neighbourhood of Corona, the highest point on the road. The tunnel will have a peak in the centre in order to ensure drainage. On the eastern side the gradient in the tunnel will be ()..'( per cent, and on the western side 0.0 per cent. The approaches on either side will be on grades not exceeding 2 per cent. The grade of the existing line is 4 por cent, so that even with four powerful Mallet engines the train loads do not exceed 22 cars, or a total weight of about H2OO tons. It is expected that when the 4 per cent grades have been eliminated one consolidation will take a train of equal weight over the section in half the time now occupied.Trains will be. worked through the tunnel by electric traction, though the steam locomotive will not be detached. The tunnel section will be 16ft by 24ft in height, timber lined, except at the portals, where concrete will be employed. The work is planned for completion in l!)2(i, and will make accessible a country about as big as France, with which hitherto communication has been of a very restricted character. It will put the whole of the products of the upper Colorado River basin into touch with the Mississippi Valley, and ia therefore expected to lead to great developments on account of the immense definitely known resources of the country which will be tapped. The mineral wealth of the region includes enormous reserves of coal, in addition to gold, silver, lead, copper and zinc, not to mention oil shales, forest lands, and so on. The Moffat road is not one of old standing, having been commenced only in l!) 02. After many vicissitudes it was completed about two years after the death of the projector, Daniel H. MofTat, from whom the road takes its popular name. The line is 245 miles in length and leaves Denver to the northwest. Over the. Divide the had to face man}- difficulties, involving costly construction. The tunnel is expected to run throughout through granite or rocks of granite character. The contract has been let for 5.200,000d01, and work is said to be progressing at the rate of JiOft per day. Penalties and bonus are provided for in the contract, and any saving on the price and recognised "p ront of 140,000d01s will be equally divided between the contractors and the commission. The contract terms included very elaborate details regarding the provision of accommodation, 4c, for the men.